Meteorological Parameters And The Onset Of Chest Pain In Subjects With Acute St-elevation Myocardial Infarction

OBJECTIVE: The purpose of this study was to investigate the influence of weather on the occurrence of acute ST-elevation myocardial infarction(STEMI) in Chinese subjects.METHODS: A total of 1467 patients with acute STEMI who presented to the First Affiliated Hospital of Nanjing Medical University from 1 January 2003 to 31 December 2010 were consecutively enrolled in and included in the study. Climate data, as well as the occurrence of STEMI, were monitored at 2 am, 8 am, 2 pm, and 8 pm. Generalized additive poisson models and distributed lag non-linear model were utilized to plot the numbers of patients with STEMI within 6 hour intervals against climatological variations, after accounting for the effects of the hour and season.RESULTS: The inclusion of meteorological conditions, including observed atmospheric pressure(h Pa, hectopascal) variations during the previous three hours and temperature(°C, degrees Celsius), significantly affected the occurrence of STEMI, as measured every six hours. Compared with the 50 th percentile of atmospheric pressure, the RRs(95%CI) for the first percentile, 10 th percentile, 25 th percentile, 75 th percentile, 90 th percentile, and 99 th percentile of atmospheric pressureover lag 0 were 1.66(1.36~2.03), 1.47(1.30~1.67), 1.22(1.12~1.33), 1.16(1.07~1.25), 1.27(1.13~1.43), and 1.16(0.92~1.46), respectively. Compared to the 50 th percentile of temperature, the RRs(95%CI) for the first percentile, 10 th percentile, 25 th percentile, 75 th percentile, 90 th percentile, and 99 th percentile oftemperature over lag 0 were 0.58(0.40~0.83), 0.60(0.46~0.78), 0.69(0.57~0.83), 1.33(1.14~1.56), 1.39(1.13~1.71), and 1.17(0.84~1.63), respectively. At lag 0-7, the RR(95% CI) for the 99 th percentile for temperature was 1.82(1.01~3.27), compared to the 50 th percentile for temperature. At lag 0-14, the RR(95% CI) for the first percentile for temperature was 2.07(1.11~3.86), compared to the 50 th percentile for temperature. At lag 0-21, the RR(95% CI) for the 99 th percentile for temperature was 2.90(1.37~6.13), compared to the 50 th percentile for temperature. At lag 0-30, the RR(95% CI) for the 99 th percentile for temperature was 2.69(1.17~6.17), compared to the 50 th percentile for temperature.CONCLUSIONS: Based on the eight-year, single-center study, significant relationships were observed among the occurrence of STEMI and atmospheric pressure during the previous three hours and temperature after account for long-term time trends.